Question

我有一个查询，我无法将最后一行columb名称的名称更改为＆＃39; TOTAL＆＃39;。结果给出了与最后一行上方行相同的名称。这是我的疑问：

SELECT COALESCE(ticket_types.name,'TOTAL') AS name, 
COUNT(1) AS quantity 
FROM tr_logs 
LEFT JOIN tickets ON tr_logs.value = tickets.id 
LEFT JOIN ticket_types ON tickets.ticket_type_id = ticket_types.id 
LEFT JOIN transactions ON tr_logs.transaction_id = transactions.id 
LEFT JOIN tr_fields_data AS tfd_shipping ON tfd_shipping.transaction_id = transactions.id 
WHERE type = 'ADDITEM' 
AND transactions.event_id = '46' 
AND DATE(tr_logs.created_date) 
BETWEEN '2017-03-26' AND '2017-05-24' 
AND tfd_shipping.data IN ('0','570','571','771') 
AND name IS NOT NULL
GROUP BY ticket_types.id WITH ROLLUP

结果如下：

name      quantity
premium   56
outlaw    6
outlaw    62

汇总的最后一行名称不为空....我需要它是TOTAL而不是outlaw

由于

Answer 1

您还没有将名称更改为TOTAL：您已将列名更改为name，并且您已将其更改为“{1}}”带有TOTAL的空值。

如果您想将ticket_types.name的名称更改为total，您只需要

SELECT ticket_types.name AS total ...

（但将名为name的内容重命名为total会很奇怪，所以您可能需要稍微澄清一下您的要求。）

Answer 2

这可能与您观察到的问题有关，但WHERE和GROUP BY子句将所有外连接转换为内连接。您应该将查询简化为：

SELECT COALESCE(tt.name, 'TOTAL') AS name, COUNT(1) AS quantity 
FROM tr_logs l JOIN
     tickets
     ON l.value = t.id JOIN
     ticket_types tt
     ON t.ticket_type_id = tt.id JOIN
     transactions tr
     ON l.transaction_id = tr.id JOIN
     tr_fields_data fd
     ON fd.transaction_id = tr.id 
WHERE type = 'ADDITEM' AND
      tr.event_id = '46' AND
      DATE(l.created_date) BETWEEN '2017-03-26' AND '2017-05-24' AND 
      fd.data IN ('0', '570', '571', '771') AND
      tt.name IS NOT NULL
GROUP BY tt.id WITH ROLLUP

Answer 3

感谢Gordon Linoff，我已经弄清楚了我的问题。

最后一行的名称永远不会为null，因为我的GROUP BY具有不同的属性。

这是解决方案。

SELECT COALESCE(tckn,'TOTAL') AS name, quantity FROM
(SELECT tt.name AS tckn, COUNT(1) AS quantity 
FROM tr_logs AS l
LEFT JOIN tickets AS t ON l.value = t.id 
LEFT JOIN ticket_types AS tt ON t.ticket_type_id = tt.id 
LEFT JOIN transactions AS tr ON l.transaction_id = tr.id 
LEFT JOIN tr_fields_data AS tfd ON tfd.transaction_id = tr.id 
WHERE type = 'ADDITEM' 
AND tr.event_id = '46' 
AND DATE(l.created_date) 
BETWEEN '2017-03-26' AND '2017-05-24' 
AND tfd.data IN ('0','570','571','771')
GROUP BY tckn WITH ROLLUP) as sum;

coalesce（）的sql问题无法正常工作

3 个答案: